Turning and milling aluminum - know-how and experience are crucial
Aluminum is a frequently used material in the production of turned and milled parts. The properties of the material, the selection of alloys and tools, the use of the optimum cutting parameters are challenges that Beutter masters optimally with a great deal of know-how and experience.
What is aluminum?
Aluminum is one of the most common metals, not only in the earth's crust. It is also very often used for industrial applications. Aluminum is one of the so-called light metals (density 2.7g/cm3). Its low specific weight is also one of its most important material properties.
How is aluminum made?
Aluminum occurs in nature almost only in bound form as aluminum ore. The most commonly used aluminum ore for industrial purposes is "bauxite". It comes mainly from the equatorial regions of Brazil, Africa and Australia.
The extraction of aluminum from aluminum ore is a very energy-intensive process. For this reason, so-called secondary aluminum is frequently used today, which is obtained through much less energy-intensive recycling.
What properties has aluminum?
Aluminum is a very light metal. It has a specific gravity that is about one-third that of steel. It is very thermally conductive and has good electrical conductivity. Very important is also the high corrosion resistance, which can be further increased by anodizing the aluminum or aluminum alloy after turning and milling.
Properties of aluminum:
- High corrosion resistance
- Good electrical conductivity
- Good heat conductor
- High stability of solid aluminum alloys
- Excellent recyclability
Pure aluminum has a tensile strength of only 45N/mm2 and a melting point of 660.3 °C. Both are insufficient for turning or milling, as it can already undergo massive deformation when heated, even long before the melting point. Pure aluminum is therefore virtually unsuitable for turning. It is virtually not used industrially due to these material properties.
In what form can aluminum be turned or milled?
Aluminum and its alloys are considered to have good machinability. However, grades with low strength can form long chips and easily stick to the cutting edge (smearing effect). Aluminum alloys with beryllium, copper, magnesium, manganese, nickel or zinc are almost exclusively used for turning and milling. The higher the strength of the alloy, the more suitable it is for turning and milling. Aluminum alloys achieve a tensile strength of 200 to 450 N/mm2. In extreme cases, up to 700N/mm2.
Work-hardened or age-hardened aluminum alloys are best suited for turning and milling. The chip removal behavior improves as the strength of the alloys increases. The addition of lead, which was still common a few years ago - and which improves the machining properties - is now only permitted up to a level of 0.4% due to the RoHS Directive (Directive on the Restriction of the Use of Certain Hazardous Substances in Waste Electrical and Electronic Equipment). The alternative is to use tin as a chipbreaking element.
Challenges in the machining of aluminum turned parts and milled parts
Depending on their composition, aluminum alloys have altered properties, e.g. in terms of strength, ductility (deformability) and corrosion resistance. Different strengthening and hardening processes also influence the properties.
Aluminum and its alloys are well suited for high-speed machining.
The selection of the right alloy, suitable for the workpiece and the machining process, requires a lot of experience.
Experience counts! The ideal cutting parameters for turning and milling aluminum
Not only the properties of the material and the composition of the alloy play a role in the machining of aluminum, but also the selection of the right machining parameters.
- Cutting speed
- tool quality
For the cutting speed, i.e. the cutting depth and the feed rate of the tools, the composition of the alloy is important. Especially the proportion of silicon and the thus changing strength of the alloy plays a decisive role for the correct cutting parameters. This ensures good cutting results and optimum chip removal.
Main application areas of aluminum turned parts, aluminum milled parts and the material aluminum
- Aerospace industry
- Automotive engineering
- Mechanical Engineering
- Plant engineering
Beutter is the specialist for aluminum turned parts, aluminum milled parts and the machining of aluminum in small series with a high vertical range of manufacture. We offer many years of experience in developing solutions for customers and support you from parts and production planning to the finished product.
Do you have any questions? We will be happy to support you with our comprehensive know-how.
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